Unless otherwise indicated herein, the description in this section is not prior art to the claims in this application and is not admitted to be prior art by inclusion in this section.
To prevent an illegal operation involving the impersonation of a person, an authentication function for a user is required for an electronic apparatus. In a typical electronic apparatus, authentication in which authentication information (such as a password) is input via an input device has been widely used. However, at the time of input, if the motion of the hand of the user and the input device of the electronic apparatus are seen by a third person, the input information may be leaked to the third person.
To solve this problem, an input device that prevents input information from being known by the third person has been proposed. This input device includes a voice generating unit that generates a voice, and performs an input operation based on information obtained by the sense of hearing in addition to the sense of vision of the user. Accordingly, even if the motion of the hand of the user and the input unit of the electronic apparatus are seen by a third person, this input device prevents leakage of the input information.
In addition to the input device using the voice, an input device that can read biological information of a human is examined. In this input device, physical features (such as fingerprints and the iris) of a human are input so as to prevent information leakage due to a furtive glance by a third person.